This invention relates to a microtome for continuously cutting thin sections of specimens for electronmicroscopic examination. More particularly, it relates to a microtome employing electromagnetic means for the control of specimen cutting.
In a conventional microtome as illustrated in FIG. 1, a schematic front view of a conventional microtome, one end 4a of a lever 4 is fitted through a hinge 3 to a lever support 2 on a base 1. To the other end 4b of the lever 4 is attached a specimen holder 7 that holds a specimen 7a opposite to a knife 6 mounted on an inching stand 5. The specimen 7a is shown as being cut by moving up and down the lever 4 by means of a cord 9 having one end connected to a pulley 8 adapted to be reciprocatingly turned through a desired angle as indicated by the arrow, and having another end connected to lever 4 between hinge 3 and specimen holder 7.
In continuous cutting, the second and subsequent thin sections of the specimen 7a have been obtained by similarly operating the pulley 8 after sliding the inching stand 5 little toward the specimen 7a or thermally expanding the lever 4 by energizing an electric heater 10 wound therearound.
In such a known microtome, only the apparent cutting speed is controlled by externally regulating the motion of the lever 4 by its own weight. Therefore, it is difficult to accurately control the speed with which the specimen 7a is cut. Further, external vibrations add to the motion of the lever 4 because only one end thereof is cantilevered by the hinge 3. It has consequently been difficult to stably obtain continuously cut thin sections of the specimen 7a.
This invention is intended for solving the aforementioned problems. The object of this invention is to provide such a microtome as permits accurate control of the specimen cutting speed irrespective of its posture, stable production of continuously cut thin sections of specimen, and realization of an automated specimen cutting cycle, by use of electromagnetic means for the control of specimen cutting.